improvement: Make sure Scala CLI tests are less flaky

[tgodzik]

The expected list should be stable and we only check if the expected subset is contained

[hamzaremmal]

This is a big improvement but I still think that we need to have a very clear policy on what are we allowed to add in the tests

[tgodzik]

What could be a potential policy? I can remove the tests if this is a problem.

[rochala]

Wouldn't it be best if we completely remove dependency on coursier and provide CoursierCompletions via interface, just like we do with Symbol search ?

[hamzaremmal]

What could be a potential policy? I can remove the tests if this is a problem.

@tgodzik In my opinion, we should not use dependencies outside of our control. For these tests, (if its not possible to test with some mock system) we can publish some kind of dummy library on Maven Central and use it instead of using com.lihaoyi::pprint, io.circe::circe-core, ...

[tgodzik]

Wouldn't it be best if we completely remove dependency on coursier and provide CoursierCompletions via interface, just like we do with Symbol search ?

Probably yeah. Or just use symbol search, add searchDependency method.